Kepa has seen himself relegated to a backup role with manager Frank Lampard announcing Edouard Mendy as his No1 goalkeeper.
“I'm very surprised," Zola, who worked with Kepa as Blues assistant manager, told talkSPORT. “I know he is very young and he came to Chelsea for big money and that is a big burden to carry on your shoulders, and in a way this is probably affecting him.
“I could understand a little bit of difficulty, but this is going beyond what was expected and it surprised me.
“And I am sorry for the boy because he is a good boy and a good goalkeeper.
“He has to pick himself up and do what he can do and show people he is different, because I believe he has got potential."